The Heineken Cup used to be a fairly simple business once the hectic stages of qualifications from the pools were over. Two questions presented themselves: who was going to win it and whose turn was it, perhaps while answering that first question, to beat Munster?

Actually, Munster were also-rans for the first four years. But in 2000 they made it to the Twickenham final, where they lost to Northampton, and since then they have been fixtures in the last eight, losing only two quarter-finals, to Biarritz in 2005 and the Scarlets in 2007.

They lost two semi-finals "away" in France (without being in the home ground of their opponents) by a single point, 16-15 to Stade Français in 2001, and 13-12 to Toulouse in 2003. The other semi they lost was at Lansdowne Road, perhaps the most dramatic game over 80 minutes in the history of the competition, 37-32 to Wasps.

Another final was lost, to Leicester in the "hand of Back" game in Cardiff in 2002. Munster's trail of near-misses didn't quite stretch back into the monochrome depths of Ireland's 1948 grand slam, but every year fairly broke a few more hearts down in Limerick and Cork and all points in between.

They finally won the Heineken Cup in 2006 and just for good measure won it again last year, prompting a different question: who can now prevent Munster from winning the Heineken Cup three times in four years?

On current form, not the Ospreys who travel to Thomond Park a week today. The Welsh region seem to have parked themselves in the same pigeonhole as ever: marvellous individuals, flimsy team. Last week's EDF Energy semi-final defeat to Gloucester was one to watch from behind the sofa.

The Ospreys have two coaches, Sean Holley and Jon Humphreys, working to CEO Andrew Hore, a New Zealander who was fitness conditioner to the Wales team before going home to acquire experience in senior management. After the Ospreys' exit to Saracens at this stage last season in the Heineken Cup, Hore showed then coach Lyn Jones the door and promoted his two assistants, without ever letting them believe they were cemented into their jobs.

And here they all are, one year on, the three of them so wobbly in their posts that defeat in Limerick could see them easily toppled. April is a cruel month for sackings.

Should Munster, super-glued as a family, beat the Ospreys then who else might stop them? Well, it could be the nominees for most improved club in Europe, Harlequins. Heaven knows what a conversation between coach Dean Richards, who lets the occasional word slide out of the corner of his mouth, and CEO Mark Evans, whose personal motto is: why use one word when a thousand can be fitted in?

But the partnership is working sweetly, with memories fresh of the Heineken Cup double over Stade Français, and the surge up the Guinness Premiership. Danny Care, Ugo Monye and Nick Easter have returned from international duty eager to be involved, which confirms that something very positive was going on with England by the end of the Six Nations.

From serial visitors to the sin bin, England have emerged as the side right now probably best avoided, and the squad players have taken this revitalised confidence back to their clubs. At the same time, they are also being kept on their toes by the form of the players like Tom Guest, who have doing more than just filling in during their absence. There is a solidarity under Will Skinner and Richards that is almost Munster-like, and certainly reminiscent of old Leicester, whence both captain and coach came.

The problem for Harlequins is that should they beat Leinster at home they would have to go to Ireland for a semi against Munster. They did the improbable against Stade in Paris, but this would be intensity on another level

If there is to be a surprise by one of the teams in the "most improved" category it could be the Cardiff Blues. They face Toulouse at the Millennium Stadium in the quarter-final and if they win that they have home advantage in the semi against the winners of Leicester and Bath, who make it three English clubs in the last eight. How far removed we are now from the autumn days when all was gloom around the England team and the English club game.

The Blues were the Ospreys' prototype for failing to be the sum of their parts. Big match days used to leave their supporters squirming. This time last year they were about to be thumped 41-17 in Toulouse.

But the Blues have toughened up. An away win in Biarritz inspired an unbeaten run in the pool stages and they have a special No8 in Xavier Rush. Only Italy's Sergio Parisse might be ahead of the ex All Black in what he is to his team.

Even so, it is hard to see Munster being derailed. The draw is with them and they seem immune to any notion that they might have done enough.

Many of them have, however, already been on an incredibly draining adventure with Ireland. A grand slam must take its toll, especially the first for 61 years. Who might beat Munster? Perhaps only Munster themselves, and the advice would be to make the wager on them failing tiny.